Digital video capabilities can be incorporated into a wide range of devices, including digital televisions, digital direct broadcast systems, wireless broadcast systems, personal digital assistants (PDAs), laptop or desktop computers, digital cameras, digital recording devices, digital media players, video gaming devices, video game consoles, cellular or satellite radio telephones, video teleconferencing devices, and the like. Digital video devices implement video compression techniques, such as those described in the standards defined by MPEG-2, MPEG-4, ITU-T H.263 or ITU-T H.264/MPEG-4, Part 10, Advanced Video Coding (AVC), the High Efficiency Video Coding (HEVC) standard presently under development, and extensions of such standards, to transmit and receive digital video information more efficiently.
Video compression techniques perform spatial prediction (intra-picture) and/or temporal prediction to reduce or remove redundancy inherent in video sequences. For block-based video coding, a video frame or slice (i.e., a picture or a portion of a picture) may be partitioned into video blocks, which may be referred to as treeblocks, coding units (CUs) and/or coding nodes. Each block can be further partitioned. Video blocks in an intra-coded (I) frame or slice of a picture are encoded using spatial prediction with respect to reference samples in neighboring blocks in the same picture. Video blocks in an inter-coded (P or B) frame or slice of a picture may use spatial prediction with respect to reference samples in neighboring blocks in the same picture or temporal prediction with respect to reference samples in other reference pictures.
Spatial or temporal prediction results in a predictive block for a block to be coded. Residual data represents pixel differences between the original block to be coded and the predictive block. An inter-coded block is encoded according to a motion vector that points to a block of reference samples forming the predictive block, and the residual data indicating the difference between the coded block and the predictive block. An intra-coded block is encoded according to an intra-coding mode and the residual data. For further compression, the residual data may be transformed from the pixel domain to a transform domain, resulting in residual transform coefficients, which then may be quantized. The quantized transform coefficients, initially arranged in a two dimensional array, may be scanned in order to produce a one-dimensional vector of transform coefficients, and entropy coding may be applied to achieve even more compression.
Video coding standards include ITU-T H.261, ISO/IEC MPEG-1 Visual, ITU-T H.262 or ISO/IEC MPEG-2 Visual, ITU-T H.263, ISO/IEC MPEG-4 Visual and ITU-T H.264 (also known as ISO/IEC MPEG-4 AVC), including its Scalable Video Coding (SVC) and Multiview Video Coding (MVC) extensions. The latest joint draft of MVC is described in “Advanced video coding for generic audiovisual services,” ITU-T Recommendation H.264, March 2010, the entire content of which is incorporated by reference.
In addition, there is a new video coding standard, namely High-Efficiency Video Coding (HEVC), being developed by the Joint Collaboration Team on Video Coding (JCT-VC) of ITU-T Video Coding Experts Group (VCEG) and ISO/IEC Motion Picture Experts Group (MPEG). Furthermore, there are ongoing efforts to produce scalable video coding, multi-view video coding, and 3DV extensions for HEVC. The multi-view extension to HEVC, namely MV-HEVC, is being developed by the JCT-3V. Tech et al., “MV-HEVC Draft Text 3 (ISO/IEC 23008-2:201x/PDAM2),” Joint Collaborative Team on Video Coding (JCT-VC) of ITU-T SG16 WP3 and ISO/IEC JTC1/SC29/WG11, 12th Meeting, Geneva, Switzerland, January 2013, (hereinafter referred to as MV-HEVC WD 3), which as of Apr. 22, 2013, is available from http://phenix.it-sudparis.eu/jct2/doc_end_user/documents/3_Geneva/wg11/JCT3V-C1004-v4.zip, the entire content of which is incorporated herein by reference. The scalable extension to HEVC, named SHVC, is also being developed by the JCT-VC. Chen et al., “SHVC Draft Text 1,” Joint Collaborative Team on Video Coding (JCT-VC) of ITU-T SG16 WP3 and ISO/IEC JTC1/SC29/WG11, 12th Meeting, Geneva, Switzerland, January 2013, (hereinafter referred to as SHVC WD1), which as of Apr. 22, 2013, is available from http://phenix.int-evey.fr/jct/doc_end_user/documents/12_Geneva/wg11/JCTVC-L1008-v1. zip, the entire content of which is incorporated herein by reference. A recent specification draft of HEVC, HEVC text specification draft 10 and referred to as HEVC hereinafter, which is incorporated herein by reference and is available, as of Apr. 22, 2013 from: http://phenix.it-sudparis.eu/jct/doc_end_user/documents/12_Geneva/wg11/JCTVC-L1003-v34.zip.